This disclosure is directed to apparatus for clamping about a pipe, and particularly pipes to be placed at sub-sea locations. In gathering lines for underwater wells, distribution lines for offshore production platforms and the like, it is often necessary to perform underwater connections. While pipe is ordinarily joined either by welding or by bolted flange construction, underwater connections are more difficult to accomplish by these techniques. This apparatus sets forth a telescoping structure which enables a relatively quick and easily achieved clamping action whereby a pipe is joined. Certain devices of James Arnold, and the company associated with him, are set forth as the prior art. These devices are shown as, for example, in U.S. Pat. Nos. 3,860,270; 3,874,706; 4,045,054; 4,005,881; 3,997,197 and 3,944,263. Additional art is shown in U.S. Pat. Nos. 2,451,351; 3,236,544; 3,420,554; 4,153,280 and 4,371,198. Generally speaking, the present apparatus features a clamping mechanism which clamps the pipe so firmly that it takes a "bite" into the sidewall of the pipe. This assures positive engagement between the clamp mechanism and the pipe. Positive engagement is obtained by driving the exposed or outer face of the clamp mechanism into the pipe sufficiently to embed teeth in the pipe, thereby taking a bite. This bite is characterized by cutting into the pipe sufficient to deeply embed the teeth in the wall of the pipe whereby positive engagement is obtained. The outer face is preferably fabricated with a set of parallel teeth extending along the length of the face so that the teeth cut and bite the pipe, assuring a leakproof and slipproof connection.
Various and sundry fittings are also set forth utilizing the connective apparatus of this disclosure featuring a clamping ring which is driven sufficiently hard into the pipe that it forms an embedded impression in the pipe.
The clamping apparatus of this disclosure utilizes a surrounding ring with groove therein. The groove receives and supports the encircling clamp means. The encircling clamp means stands taller than groove depth. The clamp means has a face received in the groove. In addition, it has an exposed or outer face which confronts the pipe to be clamped. Moreover, this exposed face is supported on a pair of side walls so that, in cross section, the clamp means comprises an outer face for pipe contact, a pair of supporting side walls, and a back wall (as needed) to close the clamp means and thereby define a hollow ring. On the interior, the hollow cavity is provided to be inflated with suitable high pressure fluid as will be described. The side walls are more or less radially directed, except that they are formed originally with a corrugations. The corrugations in each sidewall are shaped so that the corragation folds extra material whereby side walls can be subsequently extended. When extended, the side walls are forced radially outwardly from the groove and thereby thrust the outer face against the pipe. This is accomplished with such force that a radial clamping action, not untypically less than perhaps a million pounds of hoop stress, is imparted to the outer face causing it to embed in the pipe.
The corrugations in the side walls are thus straightened to take on the shape of the surrounding groove. When straightened, they prop up the exposed outer face and hold it in a rigid fashion to assure clamping action.
Certain connective fixtures are fabricated utilizing the apparatus described to this juncture, the fixtures being shown in multiple embodiments for the purpose of constructing a quality clamp mechanism. While these and other features will be noted on a review of the detailed description written below, the structure is best understood on a review of the drawings which are first encorporated and described.